So far more than 90% of the air strikes inside Syria have been conducted by the US.

It is of course still early days. But given the limited number of UK air strikes it begs the issues to: why was the government so keen to expand the air strikes to Syria, and why the agonising over a election that appears to have changed relatively little?

It is worth recalling that David Cameron argued for Britain to join the Syria air strikes.

He said it was to deny IS, also known as Isil, a safe haven. “It is in Syria, in Raqqa, that Isil has its headquarters, and it is from Raqqa that some of the main threats against this country are planned and orchestrated, ” he said.

He argued that by authorising British air strikes over Syria, the RAF would be able to take out the “snake's head” – the leadership of IS.

Iraq priority

So why hasn't that happened? The first reason is that Syria has not been the military priority.

In Iraq air strikes are making a difference, largely because there is an army to work with on the ground.

Image copyrightAPImage caption Ramadi has been the target of both US and UK air strikes

Day-by-day the so-called “moderate rebels” are being targeted by Russian aircraft determined to bolster President Assad's position.

Surveillance key

The battle lines in Syria are blurred and constantly shifting. And it is much harder to conduct an air campaign without eyes on the ground.

However, it would be wrong to give the impression that Syria is being completely dismissed.

Image copyrightGetty ImagesImage caption Six Typhoons were deployed to RAF Akrotiri in Cyprus after the UK approved air strikes in Syria

On 19 December the US-led coalition carried out its largest ever pre-planned attack on oil installations near Raqqa, dropping 140 bombs and weapons in a single day( in the coalition daily update this was listed as simply one air strike as it involved one target ).

The US has furthermore been running after senior figures: 10 so-called “high-value targets” have been killed over the past month alone.